1. Field of the Invention
The present invention relates to a parallel signal transmission device, and in particular to a parallel signal transmission device converting serial signals into parallel signals at a transmitting unit to be transmitted to a receiving unit.
When parallel signals converted from serial signals are transmitted from a transmitting unit to a receiving unit using a plurality of signal lines, the receiving unit cannot perform a normal parallel signal processing due to skews, i.e. dispersion of data phases, generated on individual signal lines. Therefore, some skew adjustments (phase adjustments) are required.
2. Description of the Related Art
In a prior art transmission device using parallel signal lines, the period of transmission data is long enough compared to generated skews. Therefore, there has been adopted a technique of providing a simple delay circuit between the transmitting unit and the receiving unit for the adjustments, or lowering the transmission speed itself.
However, with a technological leap advance in recent years, ultrahigh-speed/high-capacity signal transmission has been made possible. For example, in an integrated circuit (IC), the period of parallel transmission data has been extremely shortened, so that the proportion of skew to the data period is increased, and the parallel data along time axis are misaligned in phase, thereby causing a problem that a normal processing cannot be performed.